To hear Susan Stamberg tell it, a degree of uncertainty goes with her job. The host of public radio's ''All Things Considered'' news program remembers the moment, not long ago, when the final segment of a story being fed from Chicago didn't quite make it to the network's Washington studio in time.
''So they flipped open my microphone and grabbed a reporter out of the hallway for me to talk to until they could get the tape on the air,'' says Ms. Stamberg, who soaked up the empty minutes with the best chitchat she could muster.
But just when Ms. Stamberg should be riding steadier in the saddle than ever - her afternoon show snaring an average weekly audience of more than 2.8 million listeners - there's a new wave of uncertainty breaking in the newsroom.
National Public Radio (NPR), which produces ''All Things Considered'' as well as the popular ''Morning Edition'' news program, is facing the most unsettling financial crisis in its 13-year history. The network recently announced that its 1983 budget deficit, estimated only six weeks ago to be $2.8 million, is actually closer to $5.8 million.
The shortfall has meant significant cuts in programming, and the network is bracing itself for even more retrenchment in the months ahead. One move being weighed: hack the length of ''All Things Considered'' in half, an option strongly opposed by local stations.
But looking beyond NPR's current financial problems, some experts see a new era emerging for public radio which could offer listeners a wider variety of programming than ever before.
''While it would be foolish not to consider this a crisis, the current situation may force us to figure out in what direction public radio needs to move to succeed 10 or 15 years down the road,'' says Wallace Smith, a member of NPR's board of directors and general manager of KUSC-FM in Los Angeles.
For the short-term, he says NPR should focus its energy and cash on what it does best - news and public affairs.
In the future, however, insiders agree public radio programming will come from a growing number of competing sources, ranging from independent producers and individual stations to small coalitions of stations and entirely new networks.
American Public Radio (APR), for instance, is a network just over a year old which distributes shows produced by local noncommercial stations. Although APR doesn't produce any programs of its own, some view it as competition for NPR.
''Public radio stations are just beginning to learn that they can shop around for programming,'' says Mr. Smith, who sits on the board of directors of APR as well as NPR.
The newer network's most popular offering is ''A Prairie Home Companion,'' produced by Minnesota Public Radio - an example of the sort of performance and entertainment programming APR has emphasized.
According to William Kling, president of APR, the network is establishing a $ 1.5 million fund that will allow it to help foster programming ideas. Once a new program is under way, however, it will be expected to pull its own financial weight through corporate or foundation underwriting.
APR could also come to the rescue of some of the programs that NPR can no longer afford to distribute. At least one program previously distributed by NPR, ''St. Paul Sunday Morning,'' is being picked up by the new network.
''The existence of APR is fortunate at this particular time, because it helps diversify the programming available to stations - but it's no a panacea,'' says Mr. Kling, who points out that APR's decentralized structure is not well suited to producing news programs such as ''All Things Considered.''
The top brass at NPR, meanwhile, is moving fast to make the most of new business ventures that could help the network free itself from government support and avoid future waves of red ink.
Earlier this month, the Federal Communications Commission cleared the way for NPR to use its satellite network for moneymaking businesses, including a national paging system and a teletext system.
The untangling of NPR's financial bind actually began in March, when the initial $2.8 million deficit was announced. The network canceled ''The Sunday Show,'' a live, five-hour arts program. At the same time, 35 staff members were dismissed and budgets for the performance and news departments were slashed.
The money problems, network officials contend, were caused mainly by a shortfall in private-sector contributions, made worse by the lingering effects of the recession.
''We expected a substantial increase in private corporation and foundation support which just didn't happen,'' says NPR president Frank Mankiewicz, who recently resigned as chief operating officer in the wake of heavy criticism. Insiders say he was warned as early as last fall that a budget crunch was inevitable.
With the most recent announcement of the larger-than-expected deficit, the network canceled the ''Dateline'' news program as well as hourly news briefs, both part of a programming package known as NPR Plus which was being used by 105 stations.
Mr. Mankiewicz says, barring any unexpected windfall, the ''Jazz Alive'' performance program will likely be dropped by the end of the year. This program is the network's third most popular, used by more than 80 percent of the 276 NPR-affiliated stations.
The network has hired an outside auditing firm to evaluate its financial standing. The results will be used by NPR's finance committee in considering various budget-balancing proposals. Ideas being batted around include borrowing money from member stations or, more likely, seeking help from the Corporation for Public Broadcasting. The CPB allocates federal funds for public radio and television and has been heavily hit by cuts in recent years.
As the financial finagling goes on, some listeners may already be noticing slight changes in NPR's news programs, such as fewer on-location reports and overseas phone interviews.